Bipost socket for luminaires

ABSTRACT

The bipost socket structure comprises a pair of clamp members accommodated in a housing and mounted for limited movement toward and away from each other, conductive socket elements interfitting the clamp members and operable to close about posts of a lamp upon movement of the clamp members together, and a mechanism for moving the clamp elements together. The mechanism comprises a movable clamping plate connected to one of the clamp members by coiled compression springs and a cam for moving the clamping plate against the action of the compression springs.

llnited Mates Patet [72] Inventor Richard B. Glicltrnann Sherman Oaks, Calif. [21] Appl. No. 839,386 [22] Filed July 7, 1969 [45] Patented Oct. 19, 1971 [73] Assignee Berltey/Colortran Mfg. Inc.

Burbank, Calil'i.

[54] BlllPOS'll SOCKET lFOlR LUMIINAIIRES 11 Claims, 9 Drawing Figs.

[52] US. Cl 339/75 R, 339/191 L, 339/255 R, 339/274 [51] llnt.C1 1H0lr 33/10 [50] Field oi Search 339/75-79, 92,147,191, 255, 274

[56] References Cited UNITED STATES PATENTS 2,175,883 10/1939 De Reamer 339/75T 3,4611dfl110 2,774,050 12/1956 Logan 339/79 FOREIGN PATENTS 92,552 5/1958 Denmark 339/75 Primary Examiner-loseph H. McGlynn Attorney-Flam and Flam ABSTRACT: The bipost socket structure comprises a pair of clamp members accommodated in a housing and mounted for limited movement toward and away from each other, conductive socket elements interfitting the clamp members and operable to close about posts ofa lamp upon movement of the clamp members together, and a mechanism for moving the clamp elements together. The mechanism comprises a movable clamping plate connected to one of the clamp members by coiled compression springs and a cam for moving the clamping plate against the action of the compression springs.

IHHIFOS'I SOCKET FOR LUMINAMES BACKGROUND OF THE INVENTION This invention relates to bipost lamp socket structures for luminaires or the like.

Typical prior structures utilizing screw-operated clamps leave a great deal to be desired because a little unbridled force results in the lamp posts being crushed. To overcome this hazard, lamp socket structures have been devised in which a spring mechanism is operatively interposed between the manual actuator and the closable socket elements. However, such structures are quite bulky and for that reason not compatible with compact luminaires of the open reflector type.

The primary object of this invention is to provide a socket structure in which spring devices serve as the operative connection between the manual actuator and the closable socket elements, but in which the entire assembly is exceedingly com pact. For this purpose, the design is executed in such manner that the overall front-toback dimension of the socket is exceedingly small, compression springs being directly interposed between the pressure plate and the clamp members. The cam for operating the pressure plate is compactly anchored.

Another object of this invention is to provide a compact socket structure of this character in which excessive adjustment of clamping force cannot harmfully affect the posts of the lamp structure. Thus, upon such excessive adjustment, insertion of the lamp structure is automatically precluded. The mechanism is thus readjusted until the posts may be inserted, and as a result, proper clamping action is achieved.

Another object of this invention is to provide a compact socket structure of this character in which the mechanism is readily operated by a flexible or rigid extension shaft. Accordingly, the socket structure is uniquely suited to luminaires in which the socket structure is otherwise inaccessible.

Another object of this invention is to provide a socket structure of this character in which electrical spacings are achieved without unduly exposing large electrically hot surfaces.

Still another object of this invention is to provide a socket structure of this character that comprises relatively few parts, some of the more important parts being duplicates of each other, and certain guide parts serving multiple functions whereby an inexpensive simple assembly is provided.

BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of the invention will be made with reference to the accompanying drawings. These drawings, unless described as diagrammatic or unless otherwise indicated, are to scale. The description of the invention is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention. Structural and operational characteristics attributed to forms of the invention first described shall also be attributed to forms later described, unless such characteristics are obviously inapplicable or unless specific exception is made. 7

FIG. I is a pictorial view of a luminaire in which a bipost socket incorporating the present invention is installed.

FIG. 2 is a top plan view of the socket, the posts of the lamp being shown in section. Parts of the bipost socket are broken away and illustrated in section.

Flg. 3 is a side elevational view of the bipost socket.

FIGS. l and are sectional views taken along planes indicated by lines 4'43 and 5-5 of FIG. 3.

FIG. 6 is a sectional view taken along a plane indicated by line 6-6 of FIG. 3, and corresponding in general to FIG. 2, but illustrating the socket in open position.

FIG. 7 is an exploded view showing the components of the bipost socket.

FIG. 8 is a pictorial view of another luminaire in which a modified socket is installed.

FIG. 9 is an enlarged side elevational view of the socket incorporated in the luminaire of FIG. 8, a portion of the luminaire housing being shown in section.

DETAILED DESCRIPTION The luminaire Ml shown in FIG. l in the present instance has a front opening 12 that may be closed, for example, by a lens structure. A reflector structure (not shown) may be located inwardly of the opening 12. Between the reflector and the opening is an electric lamp M. This lamp is provided with a pair of posts l6 and 18 (FIGS. 2 and 4i) mounted by a bipost socket structure 20. The socket structure in this instance is mounted upon a slide plate 22. The plate 212 is supported for movement longitudinally of the luminaire M) by the aid of channel-shaped guides 24S and 26. The support 22 may be moved for purposes of producing different light-radiation patterns.

In the present instance, the bipost socket structure 20 mounts the lamp 14 so that its posts 16 and 16 fall in a plane parallel to the longitudinal axis of the luminaire 110. In other applications, the posts 16 and 118 may be oriented in a trans verse plane.

One post 16 is received between a pair of electrically conductive identical socket elements 28 and 30 (see FIGS. 6 and 7) made of copper or other suitable material. The other post 116 is received between a similar pair of socket elements 32 and 34 identical to elements 28 and 36. The socket elements are generally formed as elongated rectangular parallelepipeds. Each has a V-shaped recess 36 extending along one of the long sides to engage along one side of the lamp post. The recesses 36 are just shallow enough that, upon movement of the socket elements towards each other, the posts 116 and 18 are firmly clamped against the sides of the V-shaped recesses. The socket elements 28-32 are mounted by two identical opposed clamp members 40 and 4,2. The clamp members are relatively thin and made of ceramic or other suitable insulation material. Each clamp member has two spaced generally rectangular recesses 4d on one face, each recess accommodating a socket element. The clamp members are oriented face to face with the recesses of one clamp member 430 respectively opposed to the recesses of the other clamp member 412. The top end and the bottom end of each recess is relieved to provide interlock shoulders 48 and 50 (FIG. 7) engaged by upper and intermediate flanges 52 and 54, of the corresponding socket element. The socket elements may be inserted into the clamp member recesses 44 when the clamp members are separated. When the clamp members are placed together, the socket elements are confined in the recesses and, due to the noncircular configuration of parts, confined against rotation. The V shaped recess of each socket element faces outwardly and opposes the V-shaped recess of the companion socket element. The top surfaces of the socket elements are flush with the top surfaces of the clamp members in which they are fitted.

The clamp members are guided so that their recessed faces are confined for movement toward and away from each other. For this purpose, a pair of hex-head machines screws 56 (FIG. 2) are provided. These screws are mounted on a hollow hous' ing 58The housing 58 is made, in this instance, as a machined aluminum casting. Extending inwardly from an extended flat top surface 60 of the housing is a large generally rectangular recess 64 into which the clamp members and assembled socket elements may be received. The top surfaces of the clamp members 40 and 42 (FIGS. land 5) and the top surfaces of the socket elements are flush with the housing surface 60. The upper ends of the socket elements are exposed for insertion and removal of the lamp posts l6 and 18, the surface 60 forming a land engaging the flat base of the lamp as shown in FIGS. 4 and 5.

The guide screws 56 (FIGS. 6 and 7) pass through aligned pairs of apertures 66 and 68 in the back and from wells 70 and 72 of the housing formed by the recess 64. These apertures locate the guide screws at opposite sides of the housing recess 64. One guide screw 56 fits laterally opening aligned grooves 74 and 76 at corresponding ends of the clamp member 40 and 42. The other screw 56 fits laterally opening aligned grooves 78 and 80 at the other corresponding ends of the clamp members.

The screws 56 confine the clamp members in the recess 64 and confine the clamp members for movement towards and away from each other. The degree of movement of the clamp members is limited by the spacing of the back and front walls 70 and 72 of the housing.

In order to urge the clamp members together, two coil compression springs 82 and 84 are provided. These springs extend through apertures 86 and 88 in the front wall 72. The outer face of the clamp members provides seats 90 and 92 for the inner ends of the springs. The springs are aligned with the respective pairs of socket elements.

The coil springs 82 and 84 are stressed by the aid of a pressure plate 94 positioned just outside of the front housing wall 72. The plate is guided for movement on extended cylindrical shanks 96 of the capscrews 98 that engage the frontally projecting ends of the guide screws 56. For this purpose the plate 94 has laterally opening recesses 100 (FIGS. 3 and 7) encompassing the capscrews.

The plate is actuated by a toggle and cam mechanism. This mechanism includes an anchor shaft 104, a toggle link 106 and a earn 108. The anchor 104 (FIGS. 6 and 7) extends through aligned apertures 110 and 112 in the rear and front walls 70 and 72 of the housing. The anchor has a threaded end 114 projecting beyond the rear wall 70 on which an adjustment stop nut 116 is mounted. The anchor 104 extends with clearance through aligned apertures 118 and 120 in the clamp members 40 and 42. The frontal end of the anchor 104 ter minates at the region of a generally rectangular central aperture 122 of the plate 94. The toggle link 106 is generally of U- shaped configuration, having top and bottom ears 124 and 126. These ears 124 and 126 (see also FIG. project over the square head 128 of the anchor 104. A pivot pin 130 extends through the ears 124 and 126 as well as the head 128 of the anchor.

The cam 108 has a handle part 132 from one end of which top and bottom circular cam elements 134 and 136 project. Segments of the circular cam elements 134 and 136 fit top and bottom walls 138 and 140 of the rectangular recess 122 of the pressure plate 94, the size of the segment being determined by the spacing of the side edges of the recess 122 which is less than the diameter of the cam elements 134 and 136. These side edges of the recesses locate the axis x of the circular cam elements relative to the plate. The cam 108 can be moved approximately 180 about the axis x from one position in which the handle part is on one side of the plate aperture 122 (FIG. 2) to the other position (FIG. 6) in which the handle part is on the other side of the aperture, the side edges of the recess 122 forming a seat for the circular cam elements 134 and 136.

The toggle link 106 projects into the plate recess 122 between the top and bottom circular cam elements 134 and 136. The outer end of the toggle link is eccentrically pivoted to the cam 108 by the aid of a pin 142. The diameter of the circle described by the pin 142 determines the movement of the pressure plate 94. This movement substantially exceeds the travel of the clamp members 40 and 42 permitted by the spacing of the housing walls. This ensures that springs 82 and 84 are materially stressed.

In the position of the cam 108 shown in FIG. 2, the axis x is located inwardly of the pin 142. The pressure plate is correspondingly moved whereby the compression springs 82 and 84 are stressed. The socket elements firmly close about the posts 16 and 18.

In the position shown in FIG. 6, the axis .x is located outwardly of the pin 142. The plate 94 is permitted corresponding movement. Accordingly, the posts 16 and 18 are released.

In the position of FIG. 2, the cam 108 has travelled so that the connecting pin 142 has passed beyond the position of alignment with the anchor post 104. The base of the lever 132 engages the side of the toggle link 106 to stop movement. The force exerted by the springs 82 and 84 is adjusted by the nut 1 16. If the nut is overadjusted, the springs in the open position of FIG. 6 will have residual stress, keeping the socket elements closed. If this residual stress is high, the lampposts cannot be inserted; hence, they cannot be crushed by excess spring force. The nut is adjusted to allow insertion, whereupon no more than the designed spring force is exerted in the clamped position.

As shown in FIG. 2 the adjustment nut 116, as well as the hexheads of the guide rods 56 are located quite close to the rear wall 70 of the housing. Moreover, the pressure plate 94 and the cam structure are located quite close to the front wall 72. The overall dimension of the apparatus from front to back is accordingly kept quite small, and a compact arrangement is ensured.

Electrical connections are made to the socket elements at their lower ends. Access openings 144 and 146 (FIGS. 4 and 7) in the back and front housing walls intersect the bottom of the housing recess 64. An insulation shield 148 lines the bottom of the recess 64 and has flanges 150 and 152 extending about the lower edges of the access openings 144 and 146.

The clarnp members have downwardly extending projections 154 and 156 that isolate the pairs of socket elements. Two cables 158 (FIG. 4) project rearwardly of the housing. Each cable 158 (FIG. 7) has an eyelet end 162 bent at right angles. A screw 164 passes through the eyelet and one leg of a conductive U-shaped shunt strip 166, and engages a tapped hole 167 in the corresponding socket element. The screw 164 provides a secure mechanical and electrical connection of the cable to the socket element 28. An electrical connection to the companion socket element 30 is provided by the strap 166. Thus, the other leg of the strap 166 is firmly secured to the companion socket element 30 by the aid of a screw 168, the connecting portion of the strap extending along the sides of the socket elements. Obviously, if it is desired to orient the cables at the front opening 146 of the housing, this can readily be accomplished.

In the present instance, the slide support 22 is attached by screws 170, 172 and 174 to the bottom of the housing 60. The lever 132 is readily accessible on one side (FIG. 1) when the cover of the lurninaire is opened. Other mounting arrangements are possible. For example, the housing has ears 176 and 178 (FIGS. 3 and 7) provided with guide apertures 180 and 182 cooperable with guide rods forming a part of the luminairc.

FIG. 8 illustrates a luminaire having a parabolic or ellipsoidal reflector 184. The main body of the lamp is located in the accessible outer space between the outer surface of the reflector and the housing, while the socket structure is located at the inaccessible space between the rear surface of the reflector and the housing. A slot 188 in the reflector provides access for the neck of the lamp 186 to the socket.

An operating shaft or rod 190 (FIG. 9) is secured to the lower circular cam element 136 and projects through an elongated slot 192 in the luminaire housing. Rotation of the shaft operates the clamp. When the clamp is released, the lamp 186 can be moved upwardly and then outwardly of the reflector 184 and a substitute lamp can be readily installed. The shaft 190 may be extended and made flexible to provide for remote operation. The slot 192 permits axial movement of the socket structure. The compact arrangement of parts forming the operative mechanism of the socket permits varied use.

I claim:

1. In a socket structure for a bipost lamp:

a. a pair of clamp members made of electrical insulation material and each having a pair of recesses;

b. a housing supporting said clamp members in opposed relationship so that the recesses of one of the clamp members opposes the recesses of the other of the clamp members;

c. means guiding said clamp members for limited movement toward and away from each other so that the pairs of opposed recesses close and open;

d. electrically conductive socket means supported in the pairs of opposed recesses respectively, and having elements that constrict about the posts of said lamp upon movement of said clamp members towards each other to close said opposed recewes;

e. a pressure plate having a cam seat;

f. means guiding said pressure plate for movement parallel to the direction of relative movement of said clamp members;

g. compression spring means interposed between said pres sure plate and one of said clamp members;

h. a cam seated in said cam seat;

i. anchor means confining said cam against movement away from said cam plate whereby said compression spring means maintains said cam in said seat; and

j. said cam being movable to alternate positions in one of which pressure plate is moved toward said clamp mem bers and in the other of which said pressure plate is permitted to move away from said clamp members under the influence of said compression spring means.

2. The combination as set forth in claim l in which said cam has a circular part engaging said seat, the axis of said circular part being parallel to the axis of said socket means; said anchor means including an anchor rod extending through said housing and with clearance through said clamp members, said anchor rod having one end located adjacent said cam seat, said anchor means further including a toggle link eccentrically connecting said cam to said one end of said anchor rod.

3. The combination as set forth in claim 2 in which the other end of said anchor rod carries a threaded member, the position of which along the anchor rod serves to determine the position of said anchor rod whereby the clamping force is adjusted.

i. The combination as set forth in claim 2 together with an operating shaft attached to said cam.

5. in a socket structure for a lamp having parallel terminal posts:

a. a pair of identical clamp members made of electrical insulation material and each having a pair of recesses extending inwardly from one surface of the clamp member;

b. a housing having a recess in which said clamp members the guide rods for limited movement toward and away from each other;

d. four electrically conductive socket elements, one for each clamp member recess, said socket elements interfitting said clamp members so that said socket elements are separable from said clamp members only when said clamp members are separated to a degree greater than that permitted by the housing recess; pairs of said socket elements defining socket axes and being operable to grip and release a post of said lamp upon movement of said clamp members toward and away from each other respectively;

e. a pressure plate extending along said front wall on the outside of said housing recess, and guided by the ends of said guide rods for movement parallel to said clamp mem bers; said pressure plate having an opening;

f. a pair of coiled compression springs between said pressure plate and said one clamp member, and passing through clearance apertures in the said front wall of said housing;

g. an anchor rod extending through said front and rear housing walls and having one end terminating adjacent said pressure plate opening, the other end of said anchor rod having stop means engageable with said rear housing wall to locate said one anchor rod end; h. a cam seated in said pressure plate opening; and

i. means providing a lateral degree of freedom pivotally connecting said cam to said one end of said anchor rod whereby angular movement of said cam causes movement of said pressure plate.

6. The combination as set forth in claim 5 in which said pivotally connecting means comprises a toggle link.

7. The combination as set forth in claim 5 together with an operating rod connected to said cam.

8. The combination as set forth in claim 5 in which said stop means is adjustable to determine the degree of compression of said spring means by operation of said pressure plate, over adjustment of said stop means causing said socket elements to remain closed to prevent insertion of terminal posts of said lamp.

9. The socket structure as set forth in claim l in which said housing has lateral access openings at the bottom of said housing recess and in which said socket means are accessible beneath said clamp members for connection of electrical conductors to said socket means.

110. The combination as set forth in claim 9 in which said clamp members together provide a partition dividing said access openings into separate spaces for the socket means respectively.

ll. The combination as set forth in claim it) together with an electrical insulation liner for said housing at the region of said lateral access openings. 

1. In a socket structure for a bipost lamp: a. a pair of clamp members made of electrical insulation material and each having a pair of recesses; b. a housing supporting said clamp members in opposed relationship so that the recesses of one of the clamp members opposes the recesses of the other of the clamp members; c. means guiding said clamp members for limited movement toward and away from each other so that the pairs of opposed recesses close and open; d. electrically conductive socket means supported in the pairs of opposed recesses respectively, and having elements that constrict about the posts of said lamp upon movement of said clamp members towards each other to close said opposed recesses; e. a pressure plate having a cam seat; f. means guiding said pressure plate for movement parallel to the direction of relative movement of said clamp members; g. compression spring means interposed between said pressure plate and one of said clamp members; h. a cam seated in said cam seat; i. anchor means confining said cam against movement away from said cam plate whereby said compression spring means maintains said cam in said seat; and j. said cam being movable to alternate positions in one of which pressure plate is moved toward said clamp members and in the other of which said pressure plate is permitted to move away from said clamp members under the influence of said compression spring means.
 2. The combination as set forth in claim 1 in which said cam has a circular part engaging said seat, the axis of said circular part being parallel to the axis of said socket means; said anchor means including an anchor rod extending through said housing and with clearance through said clamp members, said anchor rod having one end located adjacent said cam seat, said anchor means further including a toggle link eccentrically connecting said cam to said one end of said anchor rod.
 3. The combination as set forth in claim 2 in which the other end of said anchor rod carries a threaded member, the position of which along the anchor rod serves to determine the position of said anchor rod whereby the clamping force is adjusted.
 4. The combination as set forth in claim 2 together with an operating shaft attached to said cam.
 5. In a socket structure for a lamp having parallel terminal posts: a. a pair of identical clamp members made of electrical insulation material and each having a pair of recesses extending inwardly from one surface of the clamp member; b. a housing having a recess in which said clamp members together are fitted with the recesses of said clamp members opposed to each other; said housing recess having a front wall along which one of said clamp members extends, and a rear wall along which the other of said clamp members extends; c. a pair of guide rods extending across opposite ends of said housing recess and through the back and front walls thereof; said clamp members being engaged by said guide rods whereby said clamp members are confined in said housing recess, said clamp members bEing supported by the guide rods for limited movement toward and away from each other; d. four electrically conductive socket elements, one for each clamp member recess, said socket elements interfitting said clamp members so that said socket elements are separable from said clamp members only when said clamp members are separated to a degree greater than that permitted by the housing recess; pairs of said socket elements defining socket axes and being operable to grip and release a post of said lamp upon movement of said clamp members toward and away from each other respectively; e. a pressure plate extending along said front wall on the outside of said housing recess, and guided by the ends of said guide rods for movement parallel to said clamp members; said pressure plate having an opening; f. a pair of coiled compression springs between said pressure plate and said one clamp member, and passing through clearance apertures in the said front wall of said housing; g. an anchor rod extending through said front and rear housing walls and having one end terminating adjacent said pressure plate opening, the other end of said anchor rod having stop means engageable with said rear housing wall to locate said one anchor rod end; h. a cam seated in said pressure plate opening; and i. means providing a lateral degree of freedom pivotally connecting said cam to said one end of said anchor rod whereby angular movement of said cam causes movement of said pressure plate.
 6. The combination as set forth in claim 5 in which said pivotally connecting means comprises a toggle link.
 7. The combination as set forth in claim 5 together with an operating rod connected to said cam.
 8. The combination as set forth in claim 5 in which said stop means is adjustable to determine the degree of compression of said spring means by operation of said pressure plate, over adjustment of said stop means causing said socket elements to remain closed to prevent insertion of terminal posts of said lamp.
 9. The socket structure as set forth in claim 1 in which said housing has lateral access openings at the bottom of said housing recess and in which said socket means are accessible beneath said clamp members for connection of electrical conductors to said socket means.
 10. The combination as set forth in claim 9 in which said clamp members together provide a partition dividing said access openings into separate spaces for the socket means respectively.
 11. The combination as set forth in claim 10 together with an electrical insulation liner for said housing at the region of said lateral access openings. 